The present invention relates generally to methods and apparatus for producing carved signs, and more particularly to methods and apparatus for producing carved signs using computers.
Carving, dating long before paper was invented, can be considered one of the earliest forms of writing. Letters carved in wood provide a sense of warmth and a feeling of permanence, and can focus the attention of viewers in a most dramatic way.
Dating well beyond the Colonial Period, traditional hand-carved wood signs having gold-leafed lettering had found a deep rooted place in our culture, and over the years the manufacture of such signs has become a time-honored craft of the signmaking arts. Wood chisels and special knives are the wood crafters basic carving tools used in the time consuming process of hand carving signage works in both relieved and incised modes of carving. Traditionally gold or silver leaf coatings have been applied to the relieved and/or incised surfaces of signage works, so that natural as well as artificial light favorably reflects therefrom to improve the visibility of the signage work, and to display a sense of richness and accentuate the artistic beauty of a signage work itself.
The conventional process for producing these hand-carved gold-leafed wood signs is manual, slow and laborious, and although expensive, they are of distinct beauty and treasured by many.
Yet while hand carved wood signs with gold-leaf lettering are highly desired articles of manufacture, the traditional process by which they have been made, has tended to make them time intensive, too expensive and thus out of reach for the greater number of persons who otherwise would desire to own such a sign customized to their needs, interests and taste.
Hitherto, the art of making gold-leafed hand-carved wood signs has retained its traditional method of manufacture, with the exception of a minor development involving the use of an overhead projector to transfer a layout pattern to prepared. wood. Such a layout transfer technique is described in Volume 15 of Fine Woodworking, March 1979, in an article at pages 72-73 entitled xe2x80x9cRouted Signs: Overhead Projector Transfers Layout To Prepared Woodxe2x80x9d by Frederick Wilbur. Using architectural stick-on letters, a few parallel lines and a design concept, a sign layout is mocked-up on a piece of transparent plastic file. Using an overhead projector, the layout is transferred onto the prepared wood.
In contrast with wood carving signmakers universally eschewing, as a matter of convention, any and all computer-assistance in practicing conventional methods of manufacturing gold-leafed carved wooden signs, the signmaking industry in general, has nevertheless been effected by the application of computer-aided design, computer-aided manufacturing and computerized numerical control technology.
Hitherto, several computer-aided signmaking systems employing computer-aided design (CAD) and computer-aided manufacturing and computer numerical control (CNC) based technology, have been developed and are presently available.
However, such signmaking systems and methods using CAD/CAM technology have been limited to the production of routed and cut-out type signs. In contrast, because of its nature, the art of carving traditional gold-leafed wood carved signs has remained in the field of art wherein wood carvers use only gouges, knives, chisels and hammers. Thus, it is now in order to briefly describe in the following paragraphs, these inherently limited CAD/CAM signmaking systems and methods.
Prior art computer-aided signmaking systems allow a signmaker to design two dimensional signage works on two-dimensional CAD systems, and to cut-out or route-in characters, shapes, designs and parts thereof so designed, using cutting tools moving under the guidance of a computer-aided machining system, which includes, a computerized numerically controlled (CNC) axially rotating routing tool. However, the cutting and routing functions achieved by the prior art CAD/CAM signmaking systems are limited in several significant ways.
In general, signage works formed into signboards by prior art CAD/CAM signmaking systems, are routed thereinto by, operation of a routing tool moving in a single plane, with single pass operations. The outlines of the characters are formed by a rotating router tool bit moving in a plane, routing out uniform grooves in the signboard within the plane. Notably, the uniform grooves formed in the signboard, have the cross-sectional shape of the rotating tool bit performing the routing operation, and are identical along the entire lengths of the members of alphanumeric characters. In some cases, multiple passes of the routing tool along the character outlines is effected, often using tool bit offsetting, to provide desired finished edges, slightly modifying the original uniform groove so formed coextensively within a single plane. These routed signs bear little if any resemblance to, and lack the surface features of, traditional gold-leafed wood carved signs, the subject to which the present invention is directed.
One example of such prior art signmaking apparatus is described in the sales brochure for the xe2x80x9cSystem 48 Plusxe2x80x9d of Gerber Scientific Products, Inc. of Manchester, Conn., wherein a computer-aided signmaking system is disclosed. Specifically, the xe2x80x9cSystem 48 Plusxe2x80x9d signmaking system comprises a computer-aided manufacturing system which includes a gantry-type cutting machine which can cut or route-out letters up to 24xe2x80x3 high, or stencil-cut sign faces for backlighting. The characters so formed from the system, are square cut or beveled, with an optional finish cut. Also, the system provides control for specifying the total depth of cut, and depth of each pass of the router head. (See pages 4.74-4.76, IV System Operation of Gerber Scientific Products"" System 48 User""s Manual, Document No. 599-020174, January 1986). However, while the xe2x80x9cSystem 48 Plusxe2x80x9d signmaking system allows an operator to make any number of passes from 1xe2x80x3 to 2xe2x80x3 inches deep for efficient routing and finer surface finishes, the system is incapable of carving into a signboard, a signage work comprising characters and designs having three-dimensional incised and/or relieved surfaces for which hand-crafted gold-leafed wood carved signs are noted. In particular, the Gerber xe2x80x9cSystem 48 Plusxe2x80x9d is limited to 2 xc2xd axes of simultaneous cutting tool motion.
Another example of prior art signmaking apparatus is described in the sales brochure for the xe2x80x9cCSF 300 Computerized Sign Fabrication Systemxe2x80x9d of Cybermation Inc. of Cambridge, Mass. The brochure discloses a CAD/CAM signmaking system including a router head mounted to the carriage of a CNC gantry-type machine which is limited to 2 xc2xd axes of simultaneous motion. Sign layouts, either computer-designed or conventionally laid out, are programmed and can be called up at the machine by an operator. While the system has a library of pre-programmed geometric parts (i.e., letters and numbers in various typestyles) requiring the operator to enter only the desired dimensions, such parts do not have the three-dimensional features characteristic of traditional gold-leafed hand-carved wood signs, nor is the CSF 300 system capable of carving signs having such surface characteristics and features.
Thus, in the art of computer-assisted design and manufacture of signage works, the convention has been to use CAD systems to design two-dimensional layouts of signage works to be cut-out of or simply routed-in various signboard materials. In the latter instance, the routed surfaces formed within a single plane of a signboard, are limited to the cutting dimensions of the tool bit employed and moving in the plane thereof.
Therefore, there is no teaching or suggestion of a computer-aided method or system for producing carved signs embodying signage works which have three-dimensional surfaces akin to those characteristic of traditional hand-crafted gold-leafed wood carved signs.
Accordingly, it is a primary object of the present invention to provide a way of doing by computers and machines, that which was done by hand in order to produce carved signs having three-dimensional surfaces akin to those characteristic of hand carved gold-leafed wood carved signs.
Another object of the present invention is to provide a computer-aided method of producing carved signs which embody signage works having three-dimensional incised and/or relieved surfaces, characteristic of traditional gold-leafed hand-carved wood signs.
It is a further object of the present invention to provide a method of producing carved signs resembling traditional hand-carved gold-leafed wood signs, wherein the method uses an integration of computer-aided design (CAD), computer-aided machining (CAM), and computerized numerical control (CNC) technology.
The present invention provides a design and manufacturing method for providing computer-produced carved signs embodying signage works having complex three-dimensional surfaces.
A principal advantage of the method hereof is it allows production of a prototype carved sign within only a few minutes after the design has been completed. As for small volume or customized production, the method requires at most, only a few hours of design time and a few minutes of manufacturing time per carved sign.
Another object of the present invention is to provide a carved sign embodying a signage work formed in a signboard by an axially rotating carving tool simultaneously moving along at least three programmable axes under the controlled guidance of a computer-aided machining system.
A further object of the present invention is to provide a computer-aided method of producing carved signs embodying signage works comprising characters shapes and designs having three-dimensional incised and/or relieved complex surfaces. According to the present method, the characters are designed on a computer-aided design system by creating a three-dimensional geometric model thereof, and are carved into a signboard using a carving tool moving under the guidance of a computer-aided machining system.
Another object of the present invention is to provide a carved sign produced by such computer-aided method of design and manufacture.
It is an even further object of the present invention to provide a CAD/CAM system for producing carved signs embodying signage works having three-dimensional incised and/or relieved curved surfaces. An advantage of the design and manufacturing method of the present invention is that a signage work represented by a three-dimensional graphical and numeric model can be exactly reproduced, as a carving in signboards, thereby allowing the use of such three-dimensional signage works as trademarks and service marks, registered with the United States Patent and Trademark Office.
A further object of the present invention is to provide a method of generating on a computer-aided design system, three-dimensional computer graphic (or, geometric) models (and numerical coordinate data files for corresponding three-dimensional carving tool paths) of three-dimensional characters generated from traditional two-dimensional characters. Such computer-aided design method can be used with the method and system for producing carved signs hereof.
Another object of the present invention is to provide a method of designing three-dimensional graphical models (i.e., representations) and numerical coordinate data files of three-dimensional characters generated from two-dimensional characters, using parametric spline-curve and/or spline-surface representations in interpolating curves and surfaces, respectively.
Another object of the present invention is to provide a method of manufacturing, carved signs embodying signage work having been recorded from preexisting physical objects using three-dimensional surface coordinate measuring methods and apparatus (e.g., instrumentation), based on principles including laser-ranging, and holography.
An even further object of the present invention is to provide a method of generating three-dimensional graphical representations and corresponding numerical coordinate data files of a signage work wherein such method employs a computer-aided three-dimensional solid image processing program on the CAD system hereof. This method provides a designer with the capability of precisely mathematically subtracting (e.g., using a computational process on the CAD system), three-dimensional solid stock material from a three-dimensional solid model of a signboard which is in mathematical union with the solid model of a carving tool that is translatable within this CAD systems"" three-dimensional coordinate system, using a three-dimensional or two-dimensional stylus or a mouse. In particular, this method involves providing a solid geometric model (i.e., three-dimensional solid graphical representation) of a carving tool and of signboard constituting material, and performing therewith, three-dimensional solid-image processing. A principal advantage of this CAD method is that it provides a highly flexible way in which to render a desired three-dimensional model (e.g., graphical representation) from which can be generated, numerical coordinate data file(s) for a three-dimensional composite tool path corresponding to a signage work to be carved in a real signboard using a particular carving tool or tools of the present invention.
Yet a further object of the present invention is to provide a computer-aided carved sign design and manufacturing system on which the methods hereof can be computer-programmed, and wherein the design and manufacturing system comprises in part, a computer-aided design system that can automatically generate and display a computer-simulation of the carving tool motion required to produce the desired signage work carved in a signboard. The design and manufacturing system of the present a invention also includes a computer-aided carving system having at least a three-dimensional numerical control (NC) machining (i.e., tool path) program, supported by a CAD/CAM computer.
Other and further objects will be explained hereinafter, and will be more particularly delineated in the appended claims, and other objects of the present invention will in part be obvious to one with ordinary skill in the art to which the present invention pertains, and will, in part, appear obvious hereinafter.
The present invention uses an integration of computer-aided design, computer-aided manufacturing, and computer numerical control technology to provide a computer-aided design and manufacturing process for producing carved signs having surface properties and features characteristic of traditional hand-crafted gold-leafed wood carved signs.
In accordance with the principles of the present invention, the method for producing carved signs hereof comprises designing on a computer-aided design (CAD) system, a three-dimensional graphical model (i.e., representation) of a signage work having three-dimensional surfaces to be carved in a signboard. On the computer-aided design system, a desired mathematical (e.g., numerical) representation of the signage work is determined. Thereafter, the desired mathematical representation, which can be in one of many possible and desirable formats, is provided to a computer-aided machining (CAM) system including a CNC machine tool having a carving tool. The material constituting the signboard is removed using the carving tool moving under the controlled guidance of the computer-aided machining system, to leave in the signboard, a three-dimensional carved pattern corresponding to the three-dimensional graphical model of the signage work. The three-dimensional carved pattern in the signboard has three-dimensional surfaces corresponding to the three dimensional surfaces of the three-dimensional graphical model of the signage work.